Assembling of tubular elements

ABSTRACT

This invention relates to a tube joining element comprising a support having therein mounting means transverse to the axis of its associated tube, and an arm member with retaining edges pivotally supported by said mounting means, whereby, when said support is inserted into a tube said retaining edges are pressed by lever action of said arm against the internal surface of said tube to hold the tube joining element in said tube.

United States Patent [191 Sonolet 1451 July 3, 1973 1 ASSEMBLING OFTUBULAR ELEMENTS [76] Inventor: Henri Claude Sonolet, 32, Rue desRenaudes, Paris, France [22] Filed: May 17, 1971 [21] Appl. No.: 144,180

[52] US. Cl. 287/54 A, 287/124, 287/126,

52/726, 52/665, 52/656, 287/189.36 H (51] Int. Cl. F16b 7/04 [58] Fieldof Search 160/381; 287/54 A,

287/54 C, 126, 189.36 H, 54 B, 56, 124, 115, 2; 52/726, 665, 285, 656;135/3 R, 15 P0 [56] References Cited UNITED STATES PATENTS 3,021,1592/1962 Baek 287/54 A 1,322,801 11/1919 Lewis 287/54 C 1,354,549 10/1920Gilmer 287/127 R 1,860,866 5/1932 Marsha1l.... 287/2 3,057,024 10/1962Doremus 287/2092 B 3,345,095 10/1967 Hohenberger 287/127 R PrimaryExaminer-David .1. Williamowsky Assistant Examiner-Wayne L. SheddAtt0rney-Young & Thompson 5 7 1 ABSTRACT This invention relates to atube joining element comprising a support having therein mounting meanstransverse to the axis of its associated tube, and an arm member withretaining edges pivotally supported by said mounting means, whereby,when said support is inserted into a tube said retaining edges arepressed by lever action of said arm against the internal surface of saidtube to ho1d the tube joining element in said tube.

12 Claims, 4 Drawing Figures ASSEMBLING OF TUBULAR ELEMENTS FIELD OF THEINVENTION The present invention relates generally to tubejoiningelements. In particular the invention relates to elements for joiningtwo or more tubes in the production of articles of furniture.

DISCUSSION OF PRIOR ART It has been proposed to connect tubes togetherby pins or rivets. It has also been proposed to connect tubes byhammering, crimping, welding or the like. These methods can leavevisible signs of the assembly operation and often need specializedequipment. These proposed connections are often unsuitable for use inarticles of furniture as they are unsightly or have projections whichmay catch on a users clothes.

OBJECTS OF THE INVENTION It is an object of this invention to provide ajoining element which is suitable for use in articles of furniture.

It is another object of this invention to effect the assembling oftubular elements so as to leave on the finished article no visible signof the assembly operation.

It is yet another object of the invention to provide a tube-joiningelement which permits, for example, three tubes disposed along the threeaxes of spatial rectangu lar coordinates to be rigidly joined together.

It is a further object of the invention to enable tubes to be firmlyconnected without the use of specialized equipment, such as weldinggear.

SUMMARY OF THE INVENTION The present invention provides a tube joiningelement comprising support means which can be inserted longitudinallyinto a tube and having a surface to contact the internal surface of atube, mounting means in said support and transverse with respect to thelongitudinal axis of said tube, an arm member pivotally supported bysaid mounting means, the ends of said arm member being spaced in adirection along said longitudinal axis and extending in a direction awayfrom said surface on said support means, wherein a first end of said armmember is capable of being inserted freely into the tube, if necessaryby beingretracted transversely of said longitudinal axis by free pivotalmovement by the arm member into said support, the second end of saidarmmember having a profile which permits it to be inserted forceably intothe tube by sliding against the end of said tube, wherein such insertionof said second end can press said second end transversely against theinterior of said tube while simultaneously pressing said first endagainst the internal surface of said tube, whereby said tube can be heldto said tube joining element by tight contact of the internal surface ofsaid tube with said contact surface of the support and with the firstand second ends of said arm member.

The present invention also provides a tube joining element which can beinserted longitudinally into two axially aligned tubes to hold the twotubes in an assembled position, comprising support means havinga surfaceto contact the internal surfaces of the two tubes, mounting means insaid tube and transverse with respect to the longitudinal axes of saidtubes, and arm member pivotally supported by said mounting means, theends of the arm member being spaced in a direction along said axes andextending in a direction away from said surface on said support means,wherein a first end of said arm member is capable of being insertedfreely into a first of said tubes, if necessary by being retractedtransversely of said axes by free pivotal movement of said arm member,the second end of the arm member having a profile which permits it to beinserted forceably into the second tube by sliding against theendthereof, wherein said insertion can cause said second end to be pressedtransversely against the interior surface of the second tube while thefirstend of the arm member is pressed against the internal surface ofthe first tube, whereby the two tubes can be held to theelement by tightcontact of the first and second ends of the arm member with the internalsurfaces of the first and second tubes respectively and by close contactof said contact surface of the support with the internal surfaces of thetwo tubes.

In accordance with one embodiment of the invention, the second end ofthe arm member has a face which is inclined with respect to thelongitudinal axis of the or each tube, for facilitating the gradualinsertion of the arm member into the correspondingtube by slidingagainst the end of a tube when the joining element is forcibly pressedthereinto. a

It is of advantage for the configuration of at least one of the two endsof the arm member to have a sharp edge to engage the internal surface ofa tube once the assembly operation is completed.

The support preferably has a contact surface which is ribbed, knurled,covered with abrasive, or provided with any other suitable detent meansto increase the coefficient of friction thereof and to strengthen itscontact with the internal surface of the associated tube.

The various components used, tubes, supports and arm members, are madeof any suitable material, metal, plastics material or the like.

DESCRIPTION OF PREFERRED EMBODIMENTS.

Further features and advantages of the invention will be apparent fromthe following description relating to embodiments selected by way ofexample and illustrated, and from the accompanying drawings, in which:

FIG. 1 shows a perspective view of a rigid assembly comprising threetube joining elements according to the invention;

FIG. 2 is a cross-section taken along the line Il-II of FIG. 1;

FIG. 3 is a longitudinal section of a tube fixed to a joining elementaccording to the invention;

FIG. 4 shows an alternative embodiment.

In FIG. 1, a block 1 of cubic shape is rigidly secured to or formedintegrally with three supports 2, 3 and 4 of tube joining elementsaccording to the invention. The supports are similar to each other andare mutually perpendicular. For the sake of clarity, only one elementwill be referred to in detail. In particular, the support 4 is a tubularmember of square or rectangular section, having a longitudinal slot 6inone of its walls 5. Two walls 7 and 8 of the support 4, which areadjacent to the slotted wall, have on their internal faces bosses 9 and10 respectively. The bosses 9 and 10 support a pin 12 on which ispivoted an arm member 11. The pin 12 extends transversely with respectto the longitudinal axis 22 of the tubular member 4.

The arm member III has two ends 13 and 14 which are directed away fromwall 15 of the support 4 and which are inclined with respect to the axis22' to facilitate insertion of the ends 13 and 14 into a tube Textending in the direction of the axis ZZ. The ends 13 and 14 of themember 11 slide against the end S of the tube during insertion.

When the element is inserted into the tube T, the first end 13 of thearm member 11 passes freely into the tube without effort. Then, the endS of the tube engages the inclined face of the second end 14 and forcesit towards the interior of the support. The effect of this is to pressthe sharp edge 16 of the end 13 firmly against the internal surface ofthe tube T. Finally, as shown in FIG. 3, the tube T is held on theelement by tight contact of the ends 13 and 14 of the arm member'and thetube T is made by their respective sharp edges 16 and 17.

In the embodiment shown in FIG. 4, which is for connecting two axiallyaligned tubes T1 and T2 a support is formed by two angle members 18 and19 with their respective limb portions 20 and 21. The limb portions 20and 21 have external faces facing each other, between which is mountedan arm member 11'. Two other limb portions 22 and 23 of the two anglemembers 18 and 19 respectively are co-planar and thus form a contactsurface to contact the internal surfaces of two tubes T1 and T2. The armmember 11 is mounted between the limb portions 20 and 21 on a pin 12 andhas one end 13' similar to the end 13 of the above described embodimentwhile its other end 14' is inclined in the opposite sense to the end 14of the above described embodiment.

To join the two tubes T1 and T2 together, the element is inserted intothe tube T1, the end 13' of the arm member being retracted into theelement without effort in a direction transverse to the axis ll of thetwo tubes. The opposite end of the element is then inserted into thetube T2. The end 14' slides against the end S of the second tube and isdisplaced transversely towzards the axis ZZ, while forcing the end 13'against the internal surface of the first tube Tl. Insertion iscontinued until the respective end faces of the two tubes T1 and T2 abutagainst each other. The tubes are then strongly held together by theclose contact of their two internal surfaces with the contact surface ofthe limb portions 22 and 23 and with the ends 13 and 14' of the armmember 11'.

In these two embodiments, the external surface of the tube or tubesremains intact and shows no visible signs of the assembly operation.

As indicated above, the contact surface of the support 4 or 18, 19 whichcomes into contact with the respective tube can be treated in anysuitable manner in order to increase its co-efficient of friction.

The elements can be formed of any suitable material and can be used togreatest effect to connect tubes formed of plastics material. Theelements preferably have an arm member made of steel.

Obviously, the invention is in no way limited to the embodimentsdescribed and illustrated which are given only by way of example. Thus,the arrangements according to the invention can be applied to tubes ortubular elements of a section other than square or rectangular.

1 claim:

1. A joining element having a body with an axis for axial insertion intotube means, said body having contact means for bearing against a firstinner surface portion of said tube means and an arm member pivotallymounted thereon with two ends spaced along the axis of the body oneither side of the pivoting point for engaging a second inner surfaceportion of the tube means transversely opposite said first surfaceportion and insertable in succession into the tube means, the end firstinserted into the tube means being freely receivable therein, while thesecond end inserted is only forceably receivable into the tube meanswhen the first end is inserted with the contact means bearing againstthe first surface portion, whereby the second end tightly engages saidsecond surface portion and produces by lever action through the armmember tight engagement of the first end with the second surface portionand forces said contact means against said first surface portion.

2. An element for joining first and second tube means end to end havinga body with an axis for axial insertion partly in said first tube meansand partly in said second tube means, said element including contactmeans with first and second portions for engaging respectively saidfirst and second tube means at the inner surfaces thereof, an arm memberpivotally mounted on said body with two ends spaced along the axis ofthe body on either side of the pivoting point and located relative tosaid body axis transversely opposite said contact means and insertablein succession in said tube means, the arm end first inserted beingfreely receivable in the first tube means while the second arm endinserted is only forceably receivable in the second tube means when saidfirst and second contact means portions are in engagement respectivelywith the inner surfaces of said tube means, whereby the second endtightly engages the inner surface of said second tube means and causesby lever action through the arm member the first inserted arm end totightly engage the inner surface of said first tube means therebyforcing said contact means against the inner surfaces of both tubemeans.

3. The element of claim 1 wherein the second end inserted has a facewhich is inclined in respect to said axis in a direction to facilitateinsertion by force of said second end in a tube means by sliding of saidface against the end of said tube means.

4. The element of claim 1 wherein a said arm member end has a sharpangled contact edge for engaging the inner surface of a said tube means.

5. the element of claim 1 wherein the second end inserted has a leadingportion consisting of a face which is inclined in respect to said axisin a direction to facilitate insertion by force of said second end in atube means by sliding of said face against the end of said tube means,and a tail portion provided with a sharp angled contact edge forengaging the inner surface of said tube means.

6. The element of claim 1 wherein said tube means includes a tubesection of uniform cross-sectional shape.

7. The element of claim 2 wherein the second end inserted has a facewhich is inclined in respect to said'axis in a direction to facilitateinsertion by force of said second end in a tube means by sliding of saidface against the end of said tube means.

8. The element of claim 2 wherein a said arm member-end has a sharpangled contact edge for engaging the inner surface of a said tube means.

9. The element of claim 2 wherein the second end inserted has a leadingportion consisting of a face which is inclined in respect to said axisin a direction to facilitate insertion by force of said second end in atube means by sliding of said face against the end of said tube means,and a tail portion provided with a sharp angled contact edge forengaging the inner surface of said tube means.

10. The element of claim 2 wherein said tubemeans includes a tubesection of uniform cross-sectional shape.

11. A joining device for a tube-frame construction comprising aplurality of joining elements according to Claim rigidly assembled toeach other with the said axes thereof extending at an angle relativelyto each other.

12. A joining device for a tube-frame construction comprising a centralblock with three joining elements rigidly fixed thereto and extendingtherefrom, each joining element having a body with an axis for axialinsertion into tube means, said body having contact means for bearingagainst a first inner surface portion of said tube means and an armmember pivotally mounted thereon with two ends spaced along the axis ofthe body on either side of the pivoting point for engaging a secondinner surface portion of the tube means transversely opposite said firstsurface portion and insertable in succession into the tube means, theend first inserted into the tube means being freely receivable therein,while the second end inserted is only forceably receivable into the tubemeans when the first end is inserted with the contact means bearingagainst the first surface portion, whereby the second end tightlyengages said second surface portion and produces by lever action throughthe arm member tight engagement of the first end with the second surfaceportion and forces said contact means against said first surfaceportion.

1. A joining element having a body with an axis for axial insertion intotube means, said body having contact means for bearing against a firstinner surface portion of said tube means and an arm member pivotallymounted thereon with two ends spaced along the axis of the body oneither side of the pivoting point for engaging a second inner surfaceportion of the tube means transversely opposite said first surfaceportion and insertable in succession into the tube means, the end firstinserted into the tube means being freely receivable therein, while thesecond end inserted is only forceably receivable into the tube meanswhen the first end is inserted with the contact means bearing againstthe first surface portion, whereby the second end tightly engages saidsecond surface portion and produces by lever action through the armmember tight engagement of the first end with the second surface portionand forces said contact means against said first surface portion.
 2. Anelement for joining first and second tube means end to end having a bodywith an axis for axial insErtion partly in said first tube means andpartly in said second tube means, said element including contact meanswith first and second portions for engaging respectively said first andsecond tube means at the inner surfaces thereof, an arm member pivotallymounted on said body with two ends spaced along the axis of the body oneither side of the pivoting point and located relative to said body axistransversely opposite said contact means and insertable in succession insaid tube means, the arm end first inserted being freely receivable inthe first tube means while the second arm end inserted is only forceablyreceivable in the second tube means when said first and second contactmeans portions are in engagement respectively with the inner surfaces ofsaid tube means, whereby the second end tightly engages the innersurface of said second tube means and causes by lever action through thearm member the first inserted arm end to tightly engage the innersurface of said first tube means thereby forcing said contact meansagainst the inner surfaces of both tube means.
 3. The element of claim 1wherein the second end inserted has a face which is inclined in respectto said axis in a direction to facilitate insertion by force of saidsecond end in a tube means by sliding of said face against the end ofsaid tube means.
 4. The element of claim 1 wherein a said arm member endhas a sharp angled contact edge for engaging the inner surface of a saidtube means.
 5. The element of claim 1 wherein the second end insertedhas a leading portion consisting of a face which is inclined in respectto said axis in a direction to facilitate insertion by force of saidsecond end in a tube means by sliding of said face against the end ofsaid tube means, and a tail portion provided with a sharp angled contactedge for engaging the inner surface of said tube means.
 6. The elementof claim 1 wherein said tube means includes a tube section of uniformcross-sectional shape.
 7. The element of claim 2 wherein the second endinserted has a face which is inclined in respect to said axis in adirection to facilitate insertion by force of said second end in a tubemeans by sliding of said face against the end of said tube means.
 8. Theelement of claim 2 wherein a said arm member end has a sharp angledcontact edge for engaging the inner surface of a said tube means.
 9. Theelement of claim 2 wherein the second end inserted has a leading portionconsisting of a face which is inclined in respect to said axis in adirection to facilitate insertion by force of said second end in a tubemeans by sliding of said face against the end of said tube means, and atail portion provided with a sharp angled contact edge for engaging theinner surface of said tube means.
 10. The element of claim 2 whereinsaid tube means includes a tube section of uniform cross-sectionalshape.
 11. A joining device for a tube-frame construction comprising aplurality of joining elements according to Claim 10 rigidly assembled toeach other with the said axes thereof extending at an angle relativelyto each other.
 12. A joining device for a tube-frame constructioncomprising a central block with three joining elements rigidly fixedthereto and extending therefrom, each joining element having a body withan axis for axial insertion into tube means, said body having contactmeans for bearing against a first inner surface portion of said tubemeans and an arm member pivotally mounted thereon with two ends spacedalong the axis of the body on either side of the pivoting point forengaging a second inner surface portion of the tube means transverselyopposite said first surface portion and insertable in succession intothe tube means, the end first inserted into the tube means being freelyreceivable therein, while the second end inserted is only forceablyreceivable into the tube means when the first end is inserted with thecontact means bearing against the first surface portion, whereby thesecond end tightly enGages said second surface portion and produces bylever action through the arm member tight engagement of the first endwith the second surface portion and forces said contact means againstsaid first surface portion.